[PATCH v3 4/4] Documentation/powerpc/fadump: add additional parameter feature details

[Mahesh J Salgaonkar]

On 2025-01-23 17:12:54 Thu, Sourabh Jain wrote:
> Update the fadump document to include details about the fadump
> additional parameter feature.
> 
> The document includes the following:
> - Significance of the feature
> - How to use it
> - Feature restrictions
> 
> No functional changes are introduced.
> 
> Cc: Avnish Chouhan <avnish at linux.ibm.com>
> Cc: Brian King <brking at linux.ibm.com>
> Cc: Hari Bathini <hbathini at linux.ibm.com>
> Cc: Madhavan Srinivasan <maddy at linux.ibm.com>
> Cc: Michael Ellerman <mpe at ellerman.id.au>
> Cc: Mahesh Salgaonkar <mahesh at linux.ibm.com>
> Signed-off-by: Sourabh Jain <sourabhjain at linux.ibm.com>
> ---
>  Documentation/ABI/testing/sysfs-kernel-fadump |  3 ++-
>  .../arch/powerpc/firmware-assisted-dump.rst   | 22 +++++++++++++++++++
>  2 files changed, 24 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/ABI/testing/sysfs-kernel-fadump b/Documentation/ABI/testing/sysfs-kernel-fadump
> index 2f9daa7ca55b..b64b7622e6fc 100644
> --- a/Documentation/ABI/testing/sysfs-kernel-fadump
> +++ b/Documentation/ABI/testing/sysfs-kernel-fadump
[...]
> +-- Support for Additional Kernel Arguments in Fadump
> +   Fadump has a feature that allows passing additional kernel arguments
> +   to the fadump kernel. This feature was primarily designed to disable
> +   kernel functionalities that are not required for the fadump kernel
> +   and to reduce its memory footprint while collecting the dump.
> +
> +  Command to Add Additional Kernel Parameters to Fadump:
> +  e.g.
> +  # echo "nr_cpus=16" > /sys/kernel/fadump/bootargs_append
> +
> +  The above command is sufficient to add additional arguments to fadump.
> +  An explicit service restart is not required.
> +
> +  Command to Retrieve the Additional Fadump Arguments:
> +  e.g.
> +  # cat /sys/kernel/fadump/bootargs_append
> +
> +Note: Additional kernel arguments for fadump with HASH MMU is only
> +      supported if the RMA size is greater than 768 MB. If the RMA
> +      size is less than 768 MB, the kernel does not export the
> +      /sys/kernel/fadump/bootargs_append sysfs node.

Reviewed-by: Mahesh Salgaonkar <mahesh at linux.ibm.com>

Thanks,
-Mahesh.

> +
>  Implementation details:
>  -----------------------
>  
> -- 
> 2.48.1
> 
> 

-- 
Mahesh J Salgaonkar